A novel real-time algorithm for torsional vibration mode of generator sets based on rotation IIR filter

The shafting torsional vibration mode of generator sets reflects dynamic process of the power grid. This paper proposes a novel real-time algorithm for shafting torsional vibration mode decomposition of generator sets, which has excellent time-frequency resolution. The algorithm realizes the signal frequency resolution filtering based on classic infinite impulse response (IIR) filtering. At the same time, the inertia of the narrow-band filtering algorithm is eliminated through multi-period rotation IIR filtering and the time-frequency dynamic resolution of the modal decomposition is realized. PSCAD-based simulation verifies that the algorithm has the frequency anti-aliasing performance, and can fully reserve the time-frequency variation characteristics and can realize the multi-mode real-time decomposition of the torsional vibration perfectly. The algorithm can also be used for the time-frequency analysis in other fields.